From 9fc19d5f7354709298dcb15b3a4c7cd9a18acebf Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 14 Dec 2015 21:24:46 +0100
Subject: [PATCH 504/513] net-next: mediatek: add switch driver for mt7621

This driver is very basic and only provides basic init and irq support.
Switchdev support for this device will follow.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/net/ethernet/mediatek/gsw_mt7621.c |  284 ++++++++++++++++++++++++++++
 1 file changed, 284 insertions(+)
 create mode 100644 drivers/net/ethernet/mediatek/gsw_mt7621.c

--- /dev/null
+++ b/drivers/net/ethernet/mediatek/gsw_mt7621.c
@@ -0,0 +1,287 @@
+/*   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; version 2 of the License
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   Copyright (C) 2009-2015 John Crispin <blogic@openwrt.org>
+ *   Copyright (C) 2009-2015 Felix Fietkau <nbd@nbd.name>
+ *   Copyright (C) 2013-2015 Michael Lee <igvtee@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+
+#include <ralink_regs.h>
+
+#include "mtk_eth_soc.h"
+#include "gsw_mt7620.h"
+
+void mtk_switch_w32(struct mt7620_gsw *gsw, u32 val, unsigned reg)
+{
+	iowrite32(val, gsw->base + reg);
+}
+
+u32 mtk_switch_r32(struct mt7620_gsw *gsw, unsigned reg)
+{
+	return ioread32(gsw->base + reg);
+}
+
+static irqreturn_t gsw_interrupt_mt7621(int irq, void *_priv)
+{
+	struct fe_priv *priv = (struct fe_priv *)_priv;
+	struct mt7620_gsw *gsw = (struct mt7620_gsw *)priv->soc->swpriv;
+	u32 reg, i;
+
+	reg = mt7530_mdio_r32(gsw, 0x700c);
+
+	for (i = 0; i < 5; i++)
+		if (reg & BIT(i)) {
+			unsigned int link;
+
+			link = mt7530_mdio_r32(gsw,
+					       0x3008 + (i * 0x100)) & 0x1;
+
+			if (link != priv->link[i]) {
+				priv->link[i] = link;
+				if (link)
+					netdev_info(priv->netdev,
+						    "port %d link up\n", i);
+				else
+					netdev_info(priv->netdev,
+						    "port %d link down\n", i);
+			}
+		}
+
+	mt7530_mdio_w32(gsw, 0x700c, 0x1f);
+
+	return IRQ_HANDLED;
+}
+
+static void mt7621_hw_init(struct mt7620_gsw *gsw, struct device_node *np)
+{
+	u32 i;
+	u32 val;
+
+	/* wardware reset the switch */
+	fe_reset(RST_CTRL_MCM);
+	mdelay(10);
+
+	/* reduce RGMII2 PAD driving strength */
+	rt_sysc_m32(3 << 4, 0, SYSC_PAD_RGMII2_MDIO);
+
+	/* gpio mux - RGMII1=Normal mode */
+	rt_sysc_m32(BIT(14), 0, SYSC_GPIO_MODE);
+
+	/* set GMAC1 RGMII mode */
+	rt_sysc_m32(3 << 12, 0, SYSC_REG_CFG1);
+
+	/* enable MDIO to control MT7530 */
+	rt_sysc_m32(3 << 12, 0, SYSC_GPIO_MODE);
+
+	/* turn off all PHYs */
+	for (i = 0; i <= 4; i++) {
+		val = _mt7620_mii_read(gsw, i, 0x0);
+		val |= BIT(11);
+		_mt7620_mii_write(gsw, i, 0x0, val);
+	}
+
+	/* reset the switch */
+	mt7530_mdio_w32(gsw, 0x7000, 0x3);
+	usleep_range(10, 20);
+
+	if ((rt_sysc_r32(SYSC_REG_CHIP_REV_ID) & 0xFFFF) == 0x0101) {
+		/* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 2k) */
+		mtk_switch_w32(gsw, 0x2305e30b, GSW_REG_MAC_P0_MCR);
+		mt7530_mdio_w32(gsw, 0x3600, 0x5e30b);
+	} else {
+		/* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 2k) */
+		mtk_switch_w32(gsw, 0x2305e33b, GSW_REG_MAC_P0_MCR);
+		mt7530_mdio_w32(gsw, 0x3600, 0x5e33b);
+	}
+
+	/* (GE2, Link down) */
+	mtk_switch_w32(gsw, 0x8000, GSW_REG_MAC_P1_MCR);
+
+	/* Set switch max RX frame length to 2k */
+	mt7530_mdio_w32(gsw, GSW_REG_GMACCR, 0x3F0B);
+
+	/* Enable Port 6, P5 as GMAC5, P5 disable */
+	val = mt7530_mdio_r32(gsw, 0x7804);
+	val &= ~BIT(8);
+	val |= BIT(6) | BIT(13) | BIT(16);
+	mt7530_mdio_w32(gsw, 0x7804, val);
+
+	val = rt_sysc_r32(0x10);
+	val = (val >> 6) & 0x7;
+	if (val >= 6) {
+		/* 25Mhz Xtal - do nothing */
+	} else if (val >= 3) {
+		/* 40Mhz */
+
+		/* disable MT7530 core clock */
+		_mt7620_mii_write(gsw, 0, 13, 0x1f);
+		_mt7620_mii_write(gsw, 0, 14, 0x410);
+		_mt7620_mii_write(gsw, 0, 13, 0x401f);
+		_mt7620_mii_write(gsw, 0, 14, 0x0);
+
+		/* disable MT7530 PLL */
+		_mt7620_mii_write(gsw, 0, 13, 0x1f);
+		_mt7620_mii_write(gsw, 0, 14, 0x40d);
+		_mt7620_mii_write(gsw, 0, 13, 0x401f);
+		_mt7620_mii_write(gsw, 0, 14, 0x2020);
+
+		/* for MT7530 core clock = 500Mhz */
+		_mt7620_mii_write(gsw, 0, 13, 0x1f);
+		_mt7620_mii_write(gsw, 0, 14, 0x40e);
+		_mt7620_mii_write(gsw, 0, 13, 0x401f);
+		_mt7620_mii_write(gsw, 0, 14, 0x119);
+
+		/* enable MT7530 PLL */
+		_mt7620_mii_write(gsw, 0, 13, 0x1f);
+		_mt7620_mii_write(gsw, 0, 14, 0x40d);
+		_mt7620_mii_write(gsw, 0, 13, 0x401f);
+		_mt7620_mii_write(gsw, 0, 14, 0x2820);
+
+		usleep_range(20, 40);
+
+		/* enable MT7530 core clock */
+		_mt7620_mii_write(gsw, 0, 13, 0x1f);
+		_mt7620_mii_write(gsw, 0, 14, 0x410);
+		_mt7620_mii_write(gsw, 0, 13, 0x401f);
+	} else {
+		/* 20Mhz Xtal - TODO */
+	}
+
+	/* RGMII */
+	_mt7620_mii_write(gsw, 0, 14, 0x1);
+
+	/* set MT7530 central align */
+	val = mt7530_mdio_r32(gsw, 0x7830);
+	val &= ~BIT(0);
+	val |= BIT(1);
+	mt7530_mdio_w32(gsw, 0x7830, val);
+	val = mt7530_mdio_r32(gsw, 0x7a40);
+	val &= ~BIT(30);
+	mt7530_mdio_w32(gsw, 0x7a40, val);
+	mt7530_mdio_w32(gsw, 0x7a78, 0x855);
+
+	/* delay setting for 10/1000M */
+	mt7530_mdio_w32(gsw, 0x7b00, 0x102);
+	mt7530_mdio_w32(gsw, 0x7b04, 0x14);
+
+	/* lower Tx Driving*/
+	mt7530_mdio_w32(gsw, 0x7a54, 0x44);
+	mt7530_mdio_w32(gsw, 0x7a5c, 0x44);
+	mt7530_mdio_w32(gsw, 0x7a64, 0x44);
+	mt7530_mdio_w32(gsw, 0x7a6c, 0x44);
+	mt7530_mdio_w32(gsw, 0x7a74, 0x44);
+	mt7530_mdio_w32(gsw, 0x7a7c, 0x44);
+
+	/* turn on all PHYs */
+	for (i = 0; i <= 4; i++) {
+		val = _mt7620_mii_read(gsw, i, 0);
+		val &= ~BIT(11);
+		_mt7620_mii_write(gsw, i, 0, val);
+	}
+
+	/* enable irq */
+	val = mt7530_mdio_r32(gsw, 0x7808);
+	val |= 3 << 16;
+	mt7530_mdio_w32(gsw, 0x7808, val);
+}
+
+static const struct of_device_id mediatek_gsw_match[] = {
+	{ .compatible = "mediatek,mt7621-gsw" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mediatek_gsw_match);
+
+int mtk_gsw_init(struct fe_priv *priv)
+{
+	struct device_node *np = priv->switch_np;
+	struct platform_device *pdev = of_find_device_by_node(np);
+	struct mt7620_gsw *gsw;
+
+	if (!pdev)
+		return -ENODEV;
+
+	if (!of_device_is_compatible(np, mediatek_gsw_match->compatible))
+		return -EINVAL;
+
+	gsw = platform_get_drvdata(pdev);
+	priv->soc->swpriv = gsw;
+
+	mt7621_hw_init(gsw, np);
+
+	if (gsw->irq) {
+		request_irq(gsw->irq, gsw_interrupt_mt7621, 0,
+			    "gsw", priv);
+		mt7530_mdio_w32(gsw, 0x7008, 0x1f);
+	}
+
+	return 0;
+}
+
+static int mt7621_gsw_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	const char *port4 = NULL;
+	struct mt7620_gsw *gsw;
+	struct device_node *np;
+
+	gsw = devm_kzalloc(&pdev->dev, sizeof(struct mt7620_gsw), GFP_KERNEL);
+	if (!gsw)
+		return -ENOMEM;
+
+	gsw->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!gsw->base)
+		return -EADDRNOTAVAIL;
+
+	gsw->dev = &pdev->dev;
+
+	of_property_read_string(np, "mediatek,port4", &port4);
+	if (port4 && !strcmp(port4, "ephy"))
+		gsw->port4 = PORT4_EPHY;
+	else if (port4 && !strcmp(port4, "gmac"))
+		gsw->port4 = PORT4_EXT;
+	else
+		gsw->port4 = PORT4_EPHY;
+
+	gsw->irq = platform_get_irq(pdev, 0);
+
+	platform_set_drvdata(pdev, gsw);
+
+	return 0;
+}
+
+static int mt7621_gsw_remove(struct platform_device *pdev)
+{
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver gsw_driver = {
+	.probe = mt7621_gsw_probe,
+	.remove = mt7621_gsw_remove,
+	.driver = {
+		.name = "mt7621-gsw",
+		.owner = THIS_MODULE,
+		.of_match_table = mediatek_gsw_match,
+	},
+};
+
+module_platform_driver(gsw_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_DESCRIPTION("GBit switch driver for Mediatek MT7621 SoC");
+MODULE_VERSION(MTK_FE_DRV_VERSION);
